Filter



Feb. 6, 1940. I c. A. CAMPBELL FILTER Filed Feb. v18, 1958 l X.; t' m@ IGttornlegs n Patented Feb. 6, 1940 FILTER Charles A. Campbell,Watertown, N. Y., assignor to The New York Air Brake Company, acorporation of New Jersey Application February 18, 1938, Serial No.191,324

(Cl. 183-7l) which receives the rim 2| of a cup-shaped shell l 22. YWhen inassembled position shell 22' is held in spaced vrelation to thebottom and lside walls'v of said channel by an annular series of spacedradial Webs or lugs 23. This permits air to `dow 3 over the rim 2| tothe interior thereof, and is effective to exclude water, cinders, andother foreign matter. Drain holes 20- are provided in shell 22 to carryoff any condensate or other moisture which for any reason may be presenttherein. l.

Within the shell 22 is positioned a filtering element or insert 24 ofgenerally annular form having an axially-extending, open-ended passagetherethrough (see particularly Figs. 1 and '3) It is made up of a stripo f wire screen 25 and a strip of fabric 26 of approximately equallengths superposed and together folded longitudinally in zig-zag form toproduce a plurality of at radially extending hollow vanes 21. The edgesof the fabric extend beyond the edges of the wire screen 20 and arestapled together as clearly shown at 28.

At the ends of its inner longitudinal folds the. edge of the fabric, asshown inA Fig. 3, is provided with tabs or ears 29 each of which formsan extension of the fabric of a pair of adjoining vanes ll 21 andisinitially folded in line with the longitudinal inner fold of its pairof vanes. Tabs 29 are then bent or lapped over, 'one upon the other,

in an annular series and stitched in place with thread, the tabsserving, when the device is as- I sembled, to prevent leakage at theends of the junctions of the vanes 21. Fig. 3 indicates this,

in part, with an endv gasket in place over the folded down tabs', andalso, .in part, with the gasket broken away and certain of the tabs 23in their initial upright position.

Both the upper and lower ends of the annular filter insert are formed asabove described and both ends are provided with annular sealing gasjkets3| of fabric which are of an area approxia mating that of the ends ofthe insert.

'l Claims.

This invention relates to filters. 'I'he form shown is designedprimarily to be used. on air pumps to clean the air being drawn throughthe pump intake. Other adaptations of the dey vice, however, may beresorted to.

Filters employing a filter insert of the general type here shown, i. e.zig-zag in cross section, are known and noclaim is here made thereto.

Filters of this type have not heretofore proved satisfactory due in partto faulty design. For instance, the use of narrow felt sealing washersat either end of the insert, restricted the end compression load to arelatively small area. -This caused the wire screen or foraminousreinforcing element of the filter insert to break down and spread apartat either end with consequent chafing and excess wear.

As the insert spread,` its overall length was considerably shortened.This permitted it to Work loose and finally resulted in objectionableleakage past the lter.

The present invention overcomes these difilculties and provides lafilter element which includes end sealing washers of an areasubstantially coextensive withv the insert end which it engages.

The lter insert and the end sealingwashersare supported and constantlyurged into intimate contact within the filter housing by spring meansthus reducing to a minimum probability of rela-4 tive displacement ofthe various elements.

1n the following specification the invention will be described in detailand illustrated in the accompanying drawing in which:

Fig.v l is an axial section View of a filter deviceconstructed inaccordance with this invention. l

Fig. 2 is a fragmentary view of the lower portion of Fig. l. i

Fig. 3 is a perspective view of a portion of one end of the filterinsert or body.

Referring now to the drawing, the numeral 6 designates the head' portionof the filter unit. It

is circular in form and is provided with studs 1,

nuts 8, and a central threaded opening 9 by means of which the unit` maybe attached to the intake connection of an air pump (not shown).

Inwardly of threaded opening 9 a' pendant yoke II formed as a part 'ofhead 6 supports a hub I2 which in turn receives ano supportsa retainingbolt or pin I3. Bolt I3 is shouldered at I4' and threaded at its 'end toreceive a castellated nutA I5. Cotter pinsvIB and I1 are provided asshown to lock the retaining Abolt I3 and the nut I5 in their assembledposition.

Radially spaced flanges I8 and I9 formed about the periphery of the head6 provide a channel The filter insert 24 when assembled isV positionedat its upper end, for coacting with its annular seat `on head 6, by thetapered boss I2 and 'yoke II of the head 6. At its lower end it ispositioned and yieldably supported by means which will now be described.

A follower 32 is formed with a circular flange Y 33 which in assembledposition engages'the sealing gasket 3| and is coextensive therewith. 5o

The retaining bolt I3 projects through an opening 34 in follower 32 andreceives a combined,l spring seat and packing gland 35 positioned withinsaid follower. Packing 36 prevents air flow around either the springseat 35 or the retaining u bolt I8. A coil spring4 3l is interposedbetween spring seat Il and a second spring seat which is slidablymounted upon an extension of spring seat Il. Outward motion thereupon islimited by a snap ring 3l which is seated in a groove.

A flanged spacer 4i is received upon the lower end of the retaining boltIl and engages the lower face of spring seat Il. VSpring seat 3l engagesthe shell 22 as well as the spring 31 and as the nut Iii is screwed homethe shell 22 will bemoved to its seat in head i and firmly clamped inposition. Similarly, the coil spring l1 will be compressed and to adegree limited by engagement of spacer Il with the shoulder I4. Theresulting stress on this spring is then sufficient to support andmaintain the filter insert 24 in position and cannot be undulyincreased. l

It will be observed that in Fig. 1 of the drawing the spring 31 isstressed the maximum degree whereas in Fig. 2 it has been assumed thatsome degree of wear or compression of the .insert has occurred and thespring 31 hasexpanded somewhat, the follower 32 movingJ-'t maintain itscontact with and Support of the'in'srt 2l.

It is also to be noted that as the end sealing gaskets 3i are forcedagainst the insert ends, the tabs or ears 29 will tend to bite into thewashers and thus inhibit radial displacement of the vanes of the insert.4

While the invention has been described in some detail no necessarylimitation thereto is implied, modifications within lthe scope of theappended claims being contemplated.

What is claimed is:l

1. The combination of a filter body of generally annular form'having a.longitudinally extending passage open at its ends, said body comprisinga plurality of flat, radially-disposed, longitudinally-extending hollowvanes communicating with said passage in the body and formed by azigzag-folded, foraminous framework and a fabric cover sustained therebyand conforming thereto, said fabric cover completely covering theexterior of the lter body, including the ends of the vanes, the coverfabric onv each pair of adjoining vanes, at both ends of the filterbody, being further extended over a portion of the end adjacent thejunction of said vanes to form a radially-disposed tab folded inprolongation of the inner fold of said pair of vanes, said folded tabsalso being folded towards said body to provide an annular overlappingseries of tabs at each end of the body; annular sealing gaskets inengagement with the ends of said body, including said tabs; a headportion having an air connection and an annular seat for one of saidgaskets surrounding said connection; and means, carried by the headportion, closing the opposite endl o f the passage in said body andhaving an annular surface engaging the other of said gaskets to clampsaid gaskets, filter body and seat Itogether in close sealingengagement.

2. The combination of a filter body of gen-` erally annular form havinga longitudinally extending passage open atvits ends, said bodycomprlsinga plurality of fiat, radially-disposed,longitudinally-extending hollow vanes communicating with said passage inthe body and formed by a foraminous framework and a fabric' coveringsustained thereby; annular sealing gaskets in ensagementl with the endsof said body; a head portion having an annular seat for one of saidgaskets; a centrally positioned, pendant .yoke located on said headportion and within the passage in the filter body; a retaining pincarried by said yoke; a follower, encircling said pin. en-

gaging the other of said gaskets and closing the corresponding end ofthe passage in said filter body. said gaskets being approximatelycoextensive with said seat and said follower and of sufficient area sothat they engage large portions, at least, of the ends of the filterbody; a compression spring on said pin for constantly urging saidfollower towards said seat to clamp said follower, filter body, gasketsand annular seat in firm sealing engagement with each other, saidfollower being movable towards said annular seat, upon longitudinalshortening of the lter body and gasket assembly, to maintain saidsealing engagement; removable means on said pin for holding the springunder compression; and means for establishing an air connection withinthe said seat to the passage in said iilter body.

3. The combination of a filter body of generally annular form having alongitudinally extending passage open at its ends, said body compris inga plurality of flat, radially-disposed, longitudinally-extending hollowvanes communicating with said passage in the body and formed by aforaminous framework and a fabric covering sustained thereby; annularsealing gaskets in engagement with the ends of said body; a head portionhaving an annular seat for one of said gaskets; a centrally positioned,pendant yoke located on said head portion and within the passage in thefilter body; a retaining bolt carried by said yoke, a follower,encircling said bolt, engaging the other of said gaskets andclosing thecorresponding end of the passage in said filter body, said gaskets beingapproximately coextensive with said seat and said follower; packingmeans for preventing leakage between said follower and bolt: acompression spring on said bolt for constantly urging said followertoward said seat to clamp said follower, filter body. Baskets andannular seat in firm sealing engagement with each other, said followerbeing movable towards said annular seat, upon longitudinal shortening ofthev filter bodyl and gasket assembly, to maintain said sealingengagement; means threaded on said bolt for compressing said spring; andmeans for establishing an air connection within said seat to the passagein said .filter body.

4. The combination of a substantially rigid illter body, said body beingof generally annular form and having a longitudinally-extending passageopen at its ends; annular sealing gaskets in engagement with the ends ofsaid filter body; a head portion having an air connection and an annularseat for one of said gaskets surrounding said connection; supportingmeans on said head portion; a follower, movably mounted on saidsupporting means, closing the opposite end of the passage in said bodyand having an annular surface engaging the other of said gaskets; andresilient means on said supporting means for constantly urging thefollower towards said seat to clamp said follower, filter body, gasketsand seat together in close sealing relation, said follower being movabletowards said seat, upon longitudinal shortening of the filter body andgasket assembly, to maintain said sealing relation of the parts.

5. The combination of a substantially rigid filter body of generallyannular form having a longitudinally-extending passage open at its ends,said body comprising a plurality of flat, radiallydisposed,longitudinally-extending hollow vanes communicating with said passage inthe body and formed by a wire screen framework and a to i fabric coversustained thereby andY conformingY lter body; a head portion having anair connecnular sealing gaskets interposed between option and an annularseat for one of said gaskets surrounding said connection; supportingmeans on said head portion extending through said passage in the illterbody; a follower, slidably mounted on said suprorting means, oppositeend of the passage in said body and having an annular surface 'engaging'the other of said gasket and a spring mounted under compression on saidsupporting means for `constantly urging the follower towards saidannular seat to clamp said follower, fllter body. gaskets and seattogether in tight sealing' engagement, the follower beingv movabletowards said seat, upon longitudinal shortening of the filter body andgasket assembly, to maintain said sealing engagement of the parts,4while each of said gaskets has sumcie'nt area so that it engages atleast a. major 'portion of the area of the adjoining end of the filterbody, the annular, seat and its gasket are eoex'tensive, surface on thefollower and its gasketare coextensive.

.6. The combination of a ijlter body of generally annular form having alongitudinally-extending passage open at its ends andlongitudinallyextending, hollow fins radiating from and comnmunicatingwith said passage, said body comprising a foraminousreinforcing element and a fabric covering sustained thereby; a mounthaving anairconnection and an annular seat surrounding the same toreceive one end of said body and coact with substantial portions'oftheends of said flns whereby said connection communicates with theinterior of the body only; a follower for closing the other end of thepassage in said body and coacting with substantial portions of the otherends of said ilns: an-

posite ends of'said lter body and said seat and follower respectively.said gaskets being sub- 'stantially follower;

the ends of saidseat, uponv longitudinal closing the ally. annular formIinterior of the body only;

and said annular coextensive with said seat and said resilient means forconstantly urging said follower toward said seat to clamp said followefilter body. gaskets and annnular seat in rm sealing engagement witheach other, said follower beingv movable towards.l said annularshortening of the illter body and gasket assembly, to maintain saidsealing engagement; means for stressing said resilient means; and meansfor limiting the stress so developed.

7. VThe combination of a lter body of generhaving alongitudinally-extending passage open at its ends andlongitudinally-extending hollow iins radiating from and communicatingwith said passage, said body comprising a foraminous reinforcing elementand a fabric covering sustained thereby; a mount having an annularseries of lugs, an Aair connection and an annular seat surrounding thesame to-receive one end 'of said body and coact with substantialportions of the ends of said iins whereby said connection communicateswith the supporting means on said mount; a follower, movably mounted onsaid supporting means, :for closing the passage in said body andcoacting with substantial portions of the other ends oi! said fins;annular sealing gaskets in site ends of said lter body and said seat andfollower respectively, said gaskets being substantially coex'tensivewith said seat and said follower; resilient means on said supportingmeans for constantly urging said follower toyward said seat to clampsaid follower, illter body.

gaskets and annular seat in iirm sealing engagement with each other.said-follower being movable towards said annular seat, upon longitudinalshortening of the nlter body and gasket assemmeans with its serving toenclose and protect said nit'er body whileaordingairpessasee to theexterior thereof between said lugs.

between oppo-

